In my opinion, that whole article is as dumb as a sack full of hammers. It misses the entire point of why we should read teh classics.
Many classics are not particularly well-written, but they most certainly are timeless. They aren't timeless because they're "historical documents", and they aren't timeless because of the beautiful language. They're timeless for the same reason they're classics, which is because they tell a timeless truth about the human condition.
Shakespeare was most certainly brilliant at writing prose, but his stories remain timeless because of what he had to say, because of content. Romero and Juliet alone has probably been told a thousand times, in a thousand ways, and with a tousand variations since Shakespeare wrote it. The language changes, but the story remains timeless because Shakespeare capured young love, and struggle, and corruption, and selflessness as few others have.
It is no historical document, it's a tale still lived today, and that will still be lived by real people a thousand years from now.
How about Shakespeare's sonnet 76?
Why is my verse so barren of new pride,
So far from variation or quick change?
Why with the time do I not glance aside
To new-found methods, and to compounds strange?
Why write I still all one, ever the same,
And keep invention in a noted weed,
That every word doth almost tell my name,
Showing their birth, and where they did proceed?
O! know sweet love I always write of you,
And you and love are still my argument;
So all my best is dressing old words new,
Spending again what is already spent:
For as the sun is daily new and old,
So is my love still telling what is told.
This isn't history, this is today, it's right now, and it sounds a bell any writer should hear loud and clear.
It's content that makes the classics timeless. No one says we should write like Shakespeare, but anyone who says his writing is simply a pile of historical documents with no meaning for writer's today just doesn't get it.
Thinkers in every field, be it a musician, a doctor, a layer, a physicist, or a writer, either stands on the shoulders of those who came before, or he remains a pygmy forever.
Of course the classics are timeless, and the writer who doesn't read them is, and will remain, a pygmy.